Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 993 insertions, 0 deletions

diff --git a/drivers/platform/x86/intel/ifs/Kconfig b/drivers/platform/x86/intel/ifs/Kconfig
new file mode 100644
index 000000000..c341a27cc
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/Kconfig
@@ -0,0 +1,16 @@
+config INTEL_IFS
+	tristate "Intel In Field Scan"
+	depends on X86 && CPU_SUP_INTEL && 64BIT && SMP
+	# Discussion on the list has shown that the sysfs API needs a bit
+	# more work, mark this as broken for now
+	depends on BROKEN
+	select INTEL_IFS_DEVICE
+	help
+	  Enable support for the In Field Scan capability in select
+	  CPUs. The capability allows for running low level tests via
+	  a scan image distributed by Intel via Github to validate CPU
+	  operation beyond baseline RAS capabilities. To compile this
+	  support as a module, choose M here. The module will be called
+	  intel_ifs.
+
+	  If unsure, say N.
diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile
new file mode 100644
index 000000000..30f035ef5
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_INTEL_IFS)		+= intel_ifs.o
+
+intel_ifs-objs			:= core.o load.o runtest.o sysfs.o
diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
new file mode 100644
index 000000000..27204e3d6
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/core.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/module.h>
+#include <linux/kdev_t.h>
+#include <linux/semaphore.h>
+
+#include <asm/cpu_device_id.h>
+
+#include "ifs.h"
+
+#define X86_MATCH(model)				\
+	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,	\
+		INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
+
+static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
+	X86_MATCH(SAPPHIRERAPIDS_X),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
+
+static struct ifs_device ifs_device = {
+	.data = {
+		.integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
+	},
+	.misc = {
+		.name = "intel_ifs_0",
+		.nodename = "intel_ifs/0",
+		.minor = MISC_DYNAMIC_MINOR,
+	},
+};
+
+static int __init ifs_init(void)
+{
+	const struct x86_cpu_id *m;
+	u64 msrval;
+
+	m = x86_match_cpu(ifs_cpu_ids);
+	if (!m)
+		return -ENODEV;
+
+	if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval))
+		return -ENODEV;
+
+	if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
+		return -ENODEV;
+
+	if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
+		return -ENODEV;
+
+	ifs_device.misc.groups = ifs_get_groups();
+
+	if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&
+	    !misc_register(&ifs_device.misc)) {
+		down(&ifs_sem);
+		ifs_load_firmware(ifs_device.misc.this_device);
+		up(&ifs_sem);
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static void __exit ifs_exit(void)
+{
+	misc_deregister(&ifs_device.misc);
+}
+
+module_init(ifs_init);
+module_exit(ifs_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
new file mode 100644
index 000000000..73c8e91cf
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -0,0 +1,234 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2022 Intel Corporation. */
+
+#ifndef _IFS_H_
+#define _IFS_H_
+
+/**
+ * DOC: In-Field Scan
+ *
+ * =============
+ * In-Field Scan
+ * =============
+ *
+ * Introduction
+ * ------------
+ *
+ * In Field Scan (IFS) is a hardware feature to run circuit level tests on
+ * a CPU core to detect problems that are not caught by parity or ECC checks.
+ * Future CPUs will support more than one type of test which will show up
+ * with a new platform-device instance-id, for now only .0 is exposed.
+ *
+ *
+ * IFS Image
+ * ---------
+ *
+ * Intel provides a firmware file containing the scan tests via
+ * github [#f1]_.  Similar to microcode there is a separate file for each
+ * family-model-stepping.
+ *
+ * IFS Image Loading
+ * -----------------
+ *
+ * The driver loads the tests into memory reserved BIOS local to each CPU
+ * socket in a two step process using writes to MSRs to first load the
+ * SHA hashes for the test. Then the tests themselves. Status MSRs provide
+ * feedback on the success/failure of these steps. When a new test file
+ * is installed it can be loaded by writing to the driver reload file::
+ *
+ *   # echo 1 > /sys/devices/virtual/misc/intel_ifs_0/reload
+ *
+ * Similar to microcode, the current version of the scan tests is stored
+ * in a fixed location: /lib/firmware/intel/ifs.0/family-model-stepping.scan
+ *
+ * Running tests
+ * -------------
+ *
+ * Tests are run by the driver synchronizing execution of all threads on a
+ * core and then writing to the ACTIVATE_SCAN MSR on all threads. Instruction
+ * execution continues when:
+ *
+ * 1) All tests have completed.
+ * 2) Execution was interrupted.
+ * 3) A test detected a problem.
+ *
+ * Note that ALL THREADS ON THE CORE ARE EFFECTIVELY OFFLINE FOR THE
+ * DURATION OF THE TEST. This can be up to 200 milliseconds. If the system
+ * is running latency sensitive applications that cannot tolerate an
+ * interruption of this magnitude, the system administrator must arrange
+ * to migrate those applications to other cores before running a core test.
+ * It may also be necessary to redirect interrupts to other CPUs.
+ *
+ * In all cases reading the SCAN_STATUS MSR provides details on what
+ * happened. The driver makes the value of this MSR visible to applications
+ * via the "details" file (see below). Interrupted tests may be restarted.
+ *
+ * The IFS driver provides sysfs interfaces via /sys/devices/virtual/misc/intel_ifs_0/
+ * to control execution:
+ *
+ * Test a specific core::
+ *
+ *   # echo <cpu#> > /sys/devices/virtual/misc/intel_ifs_0/run_test
+ *
+ * when HT is enabled any of the sibling cpu# can be specified to test
+ * its corresponding physical core. Since the tests are per physical core,
+ * the result of testing any thread is same. All siblings must be online
+ * to run a core test. It is only necessary to test one thread.
+ *
+ * For e.g. to test core corresponding to cpu5
+ *
+ *   # echo 5 > /sys/devices/virtual/misc/intel_ifs_0/run_test
+ *
+ * Results of the last test is provided in /sys::
+ *
+ *   $ cat /sys/devices/virtual/misc/intel_ifs_0/status
+ *   pass
+ *
+ * Status can be one of pass, fail, untested
+ *
+ * Additional details of the last test is provided by the details file::
+ *
+ *   $ cat /sys/devices/virtual/misc/intel_ifs_0/details
+ *   0x8081
+ *
+ * The details file reports the hex value of the SCAN_STATUS MSR.
+ * Hardware defined error codes are documented in volume 4 of the Intel
+ * Software Developer's Manual but the error_code field may contain one of
+ * the following driver defined software codes:
+ *
+ * +------+--------------------+
+ * | 0xFD | Software timeout   |
+ * +------+--------------------+
+ * | 0xFE | Partial completion |
+ * +------+--------------------+
+ *
+ * Driver design choices
+ * ---------------------
+ *
+ * 1) The ACTIVATE_SCAN MSR allows for running any consecutive subrange of
+ * available tests. But the driver always tries to run all tests and only
+ * uses the subrange feature to restart an interrupted test.
+ *
+ * 2) Hardware allows for some number of cores to be tested in parallel.
+ * The driver does not make use of this, it only tests one core at a time.
+ *
+ * .. [#f1] https://github.com/intel/TBD
+ */
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+
+#define MSR_COPY_SCAN_HASHES			0x000002c2
+#define MSR_SCAN_HASHES_STATUS			0x000002c3
+#define MSR_AUTHENTICATE_AND_COPY_CHUNK		0x000002c4
+#define MSR_CHUNKS_AUTHENTICATION_STATUS	0x000002c5
+#define MSR_ACTIVATE_SCAN			0x000002c6
+#define MSR_SCAN_STATUS				0x000002c7
+#define SCAN_NOT_TESTED				0
+#define SCAN_TEST_PASS				1
+#define SCAN_TEST_FAIL				2
+
+/* MSR_SCAN_HASHES_STATUS bit fields */
+union ifs_scan_hashes_status {
+	u64	data;
+	struct {
+		u32	chunk_size	:16;
+		u32	num_chunks	:8;
+		u32	rsvd1		:8;
+		u32	error_code	:8;
+		u32	rsvd2		:11;
+		u32	max_core_limit	:12;
+		u32	valid		:1;
+	};
+};
+
+/* MSR_CHUNKS_AUTH_STATUS bit fields */
+union ifs_chunks_auth_status {
+	u64	data;
+	struct {
+		u32	valid_chunks	:8;
+		u32	total_chunks	:8;
+		u32	rsvd1		:16;
+		u32	error_code	:8;
+		u32	rsvd2		:24;
+	};
+};
+
+/* MSR_ACTIVATE_SCAN bit fields */
+union ifs_scan {
+	u64	data;
+	struct {
+		u32	start	:8;
+		u32	stop	:8;
+		u32	rsvd	:16;
+		u32	delay	:31;
+		u32	sigmce	:1;
+	};
+};
+
+/* MSR_SCAN_STATUS bit fields */
+union ifs_status {
+	u64	data;
+	struct {
+		u32	chunk_num		:8;
+		u32	chunk_stop_index	:8;
+		u32	rsvd1			:16;
+		u32	error_code		:8;
+		u32	rsvd2			:22;
+		u32	control_error		:1;
+		u32	signature_error		:1;
+	};
+};
+
+/*
+ * Driver populated error-codes
+ * 0xFD: Test timed out before completing all the chunks.
+ * 0xFE: not all scan chunks were executed. Maximum forward progress retries exceeded.
+ */
+#define IFS_SW_TIMEOUT				0xFD
+#define IFS_SW_PARTIAL_COMPLETION		0xFE
+
+/**
+ * struct ifs_data - attributes related to intel IFS driver
+ * @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test
+ * @loaded_version: stores the currently loaded ifs image version.
+ * @loaded: If a valid test binary has been loaded into the memory
+ * @loading_error: Error occurred on another CPU while loading image
+ * @valid_chunks: number of chunks which could be validated.
+ * @status: it holds simple status pass/fail/untested
+ * @scan_details: opaque scan status code from h/w
+ */
+struct ifs_data {
+	int	integrity_cap_bit;
+	int	loaded_version;
+	bool	loaded;
+	bool	loading_error;
+	int	valid_chunks;
+	int	status;
+	u64	scan_details;
+};
+
+struct ifs_work {
+	struct work_struct w;
+	struct device *dev;
+};
+
+struct ifs_device {
+	struct ifs_data data;
+	struct miscdevice misc;
+};
+
+static inline struct ifs_data *ifs_get_data(struct device *dev)
+{
+	struct miscdevice *m = dev_get_drvdata(dev);
+	struct ifs_device *d = container_of(m, struct ifs_device, misc);
+
+	return &d->data;
+}
+
+void ifs_load_firmware(struct device *dev);
+int do_core_test(int cpu, struct device *dev);
+const struct attribute_group **ifs_get_groups(void);
+
+extern struct semaphore ifs_sem;
+
+#endif
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
new file mode 100644
index 000000000..3e52b4eb1
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/firmware.h>
+#include <asm/cpu.h>
+#include <linux/slab.h>
+#include <asm/microcode_intel.h>
+
+#include "ifs.h"
+
+struct ifs_header {
+	u32 header_ver;
+	u32 blob_revision;
+	u32 date;
+	u32 processor_sig;
+	u32 check_sum;
+	u32 loader_rev;
+	u32 processor_flags;
+	u32 metadata_size;
+	u32 total_size;
+	u32 fusa_info;
+	u64 reserved;
+};
+
+#define IFS_HEADER_SIZE	(sizeof(struct ifs_header))
+static struct ifs_header *ifs_header_ptr;	/* pointer to the ifs image header */
+static u64 ifs_hash_ptr;			/* Address of ifs metadata (hash) */
+static u64 ifs_test_image_ptr;			/* 256B aligned address of test pattern */
+static DECLARE_COMPLETION(ifs_done);
+
+static const char * const scan_hash_status[] = {
+	[0] = "No error reported",
+	[1] = "Attempt to copy scan hashes when copy already in progress",
+	[2] = "Secure Memory not set up correctly",
+	[3] = "FuSaInfo.ProgramID does not match or ff-mm-ss does not match",
+	[4] = "Reserved",
+	[5] = "Integrity check failed",
+	[6] = "Scan reload or test is in progress"
+};
+
+static const char * const scan_authentication_status[] = {
+	[0] = "No error reported",
+	[1] = "Attempt to authenticate a chunk which is already marked as authentic",
+	[2] = "Chunk authentication error. The hash of chunk did not match expected value"
+};
+
+/*
+ * To copy scan hashes and authenticate test chunks, the initiating cpu must point
+ * to the EDX:EAX to the test image in linear address.
+ * Run wrmsr(MSR_COPY_SCAN_HASHES) for scan hash copy and run wrmsr(MSR_AUTHENTICATE_AND_COPY_CHUNK)
+ * for scan hash copy and test chunk authentication.
+ */
+static void copy_hashes_authenticate_chunks(struct work_struct *work)
+{
+	struct ifs_work *local_work = container_of(work, struct ifs_work, w);
+	union ifs_scan_hashes_status hashes_status;
+	union ifs_chunks_auth_status chunk_status;
+	struct device *dev = local_work->dev;
+	int i, num_chunks, chunk_size;
+	struct ifs_data *ifsd;
+	u64 linear_addr, base;
+	u32 err_code;
+
+	ifsd = ifs_get_data(dev);
+	/* run scan hash copy */
+	wrmsrl(MSR_COPY_SCAN_HASHES, ifs_hash_ptr);
+	rdmsrl(MSR_SCAN_HASHES_STATUS, hashes_status.data);
+
+	/* enumerate the scan image information */
+	num_chunks = hashes_status.num_chunks;
+	chunk_size = hashes_status.chunk_size * 1024;
+	err_code = hashes_status.error_code;
+
+	if (!hashes_status.valid) {
+		ifsd->loading_error = true;
+		if (err_code >= ARRAY_SIZE(scan_hash_status)) {
+			dev_err(dev, "invalid error code 0x%x for hash copy\n", err_code);
+			goto done;
+		}
+		dev_err(dev, "Hash copy error : %s", scan_hash_status[err_code]);
+		goto done;
+	}
+
+	/* base linear address to the scan data */
+	base = ifs_test_image_ptr;
+
+	/* scan data authentication and copy chunks to secured memory */
+	for (i = 0; i < num_chunks; i++) {
+		linear_addr = base + i * chunk_size;
+		linear_addr |= i;
+
+		wrmsrl(MSR_AUTHENTICATE_AND_COPY_CHUNK, linear_addr);
+		rdmsrl(MSR_CHUNKS_AUTHENTICATION_STATUS, chunk_status.data);
+
+		ifsd->valid_chunks = chunk_status.valid_chunks;
+		err_code = chunk_status.error_code;
+
+		if (err_code) {
+			ifsd->loading_error = true;
+			if (err_code >= ARRAY_SIZE(scan_authentication_status)) {
+				dev_err(dev,
+					"invalid error code 0x%x for authentication\n", err_code);
+				goto done;
+			}
+			dev_err(dev, "Chunk authentication error %s\n",
+				scan_authentication_status[err_code]);
+			goto done;
+		}
+	}
+done:
+	complete(&ifs_done);
+}
+
+/*
+ * IFS requires scan chunks authenticated per each socket in the platform.
+ * Once the test chunk is authenticated, it is automatically copied to secured memory
+ * and proceed the authentication for the next chunk.
+ */
+static int scan_chunks_sanity_check(struct device *dev)
+{
+	int metadata_size, curr_pkg, cpu, ret = -ENOMEM;
+	struct ifs_data *ifsd = ifs_get_data(dev);
+	bool *package_authenticated;
+	struct ifs_work local_work;
+	char *test_ptr;
+
+	package_authenticated = kcalloc(topology_max_packages(), sizeof(bool), GFP_KERNEL);
+	if (!package_authenticated)
+		return ret;
+
+	metadata_size = ifs_header_ptr->metadata_size;
+
+	/* Spec says that if the Meta Data Size = 0 then it should be treated as 2000 */
+	if (metadata_size == 0)
+		metadata_size = 2000;
+
+	/* Scan chunk start must be 256 byte aligned */
+	if ((metadata_size + IFS_HEADER_SIZE) % 256) {
+		dev_err(dev, "Scan pattern offset within the binary is not 256 byte aligned\n");
+		return -EINVAL;
+	}
+
+	test_ptr = (char *)ifs_header_ptr + IFS_HEADER_SIZE + metadata_size;
+	ifsd->loading_error = false;
+
+	ifs_test_image_ptr = (u64)test_ptr;
+	ifsd->loaded_version = ifs_header_ptr->blob_revision;
+
+	/* copy the scan hash and authenticate per package */
+	cpus_read_lock();
+	for_each_online_cpu(cpu) {
+		curr_pkg = topology_physical_package_id(cpu);
+		if (package_authenticated[curr_pkg])
+			continue;
+		reinit_completion(&ifs_done);
+		local_work.dev = dev;
+		INIT_WORK_ONSTACK(&local_work.w, copy_hashes_authenticate_chunks);
+		schedule_work_on(cpu, &local_work.w);
+		wait_for_completion(&ifs_done);
+		if (ifsd->loading_error)
+			goto out;
+		package_authenticated[curr_pkg] = 1;
+	}
+	ret = 0;
+out:
+	cpus_read_unlock();
+	kfree(package_authenticated);
+
+	return ret;
+}
+
+static int ifs_sanity_check(struct device *dev,
+			    const struct microcode_header_intel *mc_header)
+{
+	unsigned long total_size, data_size;
+	u32 sum, *mc;
+
+	total_size = get_totalsize(mc_header);
+	data_size = get_datasize(mc_header);
+
+	if ((data_size + MC_HEADER_SIZE > total_size) || (total_size % sizeof(u32))) {
+		dev_err(dev, "bad ifs data file size.\n");
+		return -EINVAL;
+	}
+
+	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
+		dev_err(dev, "invalid/unknown ifs update format.\n");
+		return -EINVAL;
+	}
+
+	mc = (u32 *)mc_header;
+	sum = 0;
+	for (int i = 0; i < total_size / sizeof(u32); i++)
+		sum += mc[i];
+
+	if (sum) {
+		dev_err(dev, "bad ifs data checksum, aborting.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool find_ifs_matching_signature(struct device *dev, struct ucode_cpu_info *uci,
+					const struct microcode_header_intel *shdr)
+{
+	unsigned int mc_size;
+
+	mc_size = get_totalsize(shdr);
+
+	if (!mc_size || ifs_sanity_check(dev, shdr) < 0) {
+		dev_err(dev, "ifs sanity check failure\n");
+		return false;
+	}
+
+	if (!intel_cpu_signatures_match(uci->cpu_sig.sig, uci->cpu_sig.pf, shdr->sig, shdr->pf)) {
+		dev_err(dev, "ifs signature, pf not matching\n");
+		return false;
+	}
+
+	return true;
+}
+
+static bool ifs_image_sanity_check(struct device *dev, const struct microcode_header_intel *data)
+{
+	struct ucode_cpu_info uci;
+
+	intel_cpu_collect_info(&uci);
+
+	return find_ifs_matching_signature(dev, &uci, data);
+}
+
+/*
+ * Load ifs image. Before loading ifs module, the ifs image must be located
+ * in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.
+ */
+void ifs_load_firmware(struct device *dev)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+	const struct firmware *fw;
+	char scan_path[32];
+	int ret;
+
+	snprintf(scan_path, sizeof(scan_path), "intel/ifs/%02x-%02x-%02x.scan",
+		 boot_cpu_data.x86, boot_cpu_data.x86_model, boot_cpu_data.x86_stepping);
+
+	ret = request_firmware_direct(&fw, scan_path, dev);
+	if (ret) {
+		dev_err(dev, "ifs file %s load failed\n", scan_path);
+		goto done;
+	}
+
+	if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data)) {
+		dev_err(dev, "ifs header sanity check failed\n");
+		goto release;
+	}
+
+	ifs_header_ptr = (struct ifs_header *)fw->data;
+	ifs_hash_ptr = (u64)(ifs_header_ptr + 1);
+
+	ret = scan_chunks_sanity_check(dev);
+release:
+	release_firmware(fw);
+done:
+	ifsd->loaded = (ret == 0);
+}
diff --git a/drivers/platform/x86/intel/ifs/runtest.c b/drivers/platform/x86/intel/ifs/runtest.c
new file mode 100644
index 000000000..b2ca2bb45
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/runtest.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/nmi.h>
+#include <linux/slab.h>
+#include <linux/stop_machine.h>
+
+#include "ifs.h"
+
+/*
+ * Note all code and data in this file is protected by
+ * ifs_sem. On HT systems all threads on a core will
+ * execute together, but only the first thread on the
+ * core will update results of the test.
+ */
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/intel_ifs.h>
+
+/* Max retries on the same chunk */
+#define MAX_IFS_RETRIES  5
+
+/*
+ * Number of TSC cycles that a logical CPU will wait for the other
+ * logical CPU on the core in the WRMSR(ACTIVATE_SCAN).
+ */
+#define IFS_THREAD_WAIT 100000
+
+enum ifs_status_err_code {
+	IFS_NO_ERROR				= 0,
+	IFS_OTHER_THREAD_COULD_NOT_JOIN		= 1,
+	IFS_INTERRUPTED_BEFORE_RENDEZVOUS	= 2,
+	IFS_POWER_MGMT_INADEQUATE_FOR_SCAN	= 3,
+	IFS_INVALID_CHUNK_RANGE			= 4,
+	IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS	= 5,
+	IFS_CORE_NOT_CAPABLE_CURRENTLY		= 6,
+	IFS_UNASSIGNED_ERROR_CODE		= 7,
+	IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT	= 8,
+	IFS_INTERRUPTED_DURING_EXECUTION	= 9,
+};
+
+static const char * const scan_test_status[] = {
+	[IFS_NO_ERROR] = "SCAN no error",
+	[IFS_OTHER_THREAD_COULD_NOT_JOIN] = "Other thread could not join.",
+	[IFS_INTERRUPTED_BEFORE_RENDEZVOUS] = "Interrupt occurred prior to SCAN coordination.",
+	[IFS_POWER_MGMT_INADEQUATE_FOR_SCAN] =
+	"Core Abort SCAN Response due to power management condition.",
+	[IFS_INVALID_CHUNK_RANGE] = "Non valid chunks in the range",
+	[IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS] = "Mismatch in arguments between threads T0/T1.",
+	[IFS_CORE_NOT_CAPABLE_CURRENTLY] = "Core not capable of performing SCAN currently",
+	[IFS_UNASSIGNED_ERROR_CODE] = "Unassigned error code 0x7",
+	[IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT] =
+	"Exceeded number of Logical Processors (LP) allowed to run Scan-At-Field concurrently",
+	[IFS_INTERRUPTED_DURING_EXECUTION] = "Interrupt occurred prior to SCAN start",
+};
+
+static void message_not_tested(struct device *dev, int cpu, union ifs_status status)
+{
+	if (status.error_code < ARRAY_SIZE(scan_test_status)) {
+		dev_info(dev, "CPU(s) %*pbl: SCAN operation did not start. %s\n",
+			 cpumask_pr_args(cpu_smt_mask(cpu)),
+			 scan_test_status[status.error_code]);
+	} else if (status.error_code == IFS_SW_TIMEOUT) {
+		dev_info(dev, "CPU(s) %*pbl: software timeout during scan\n",
+			 cpumask_pr_args(cpu_smt_mask(cpu)));
+	} else if (status.error_code == IFS_SW_PARTIAL_COMPLETION) {
+		dev_info(dev, "CPU(s) %*pbl: %s\n",
+			 cpumask_pr_args(cpu_smt_mask(cpu)),
+			 "Not all scan chunks were executed. Maximum forward progress retries exceeded");
+	} else {
+		dev_info(dev, "CPU(s) %*pbl: SCAN unknown status %llx\n",
+			 cpumask_pr_args(cpu_smt_mask(cpu)), status.data);
+	}
+}
+
+static void message_fail(struct device *dev, int cpu, union ifs_status status)
+{
+	/*
+	 * control_error is set when the microcode runs into a problem
+	 * loading the image from the reserved BIOS memory, or it has
+	 * been corrupted. Reloading the image may fix this issue.
+	 */
+	if (status.control_error) {
+		dev_err(dev, "CPU(s) %*pbl: could not execute from loaded scan image\n",
+			cpumask_pr_args(cpu_smt_mask(cpu)));
+	}
+
+	/*
+	 * signature_error is set when the output from the scan chains does not
+	 * match the expected signature. This might be a transient problem (e.g.
+	 * due to a bit flip from an alpha particle or neutron). If the problem
+	 * repeats on a subsequent test, then it indicates an actual problem in
+	 * the core being tested.
+	 */
+	if (status.signature_error) {
+		dev_err(dev, "CPU(s) %*pbl: test signature incorrect.\n",
+			cpumask_pr_args(cpu_smt_mask(cpu)));
+	}
+}
+
+static bool can_restart(union ifs_status status)
+{
+	enum ifs_status_err_code err_code = status.error_code;
+
+	/* Signature for chunk is bad, or scan test failed */
+	if (status.signature_error || status.control_error)
+		return false;
+
+	switch (err_code) {
+	case IFS_NO_ERROR:
+	case IFS_OTHER_THREAD_COULD_NOT_JOIN:
+	case IFS_INTERRUPTED_BEFORE_RENDEZVOUS:
+	case IFS_POWER_MGMT_INADEQUATE_FOR_SCAN:
+	case IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT:
+	case IFS_INTERRUPTED_DURING_EXECUTION:
+		return true;
+	case IFS_INVALID_CHUNK_RANGE:
+	case IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS:
+	case IFS_CORE_NOT_CAPABLE_CURRENTLY:
+	case IFS_UNASSIGNED_ERROR_CODE:
+		break;
+	}
+	return false;
+}
+
+/*
+ * Execute the scan. Called "simultaneously" on all threads of a core
+ * at high priority using the stop_cpus mechanism.
+ */
+static int doscan(void *data)
+{
+	int cpu = smp_processor_id();
+	u64 *msrs = data;
+	int first;
+
+	/* Only the first logical CPU on a core reports result */
+	first = cpumask_first(cpu_smt_mask(cpu));
+
+	/*
+	 * This WRMSR will wait for other HT threads to also write
+	 * to this MSR (at most for activate.delay cycles). Then it
+	 * starts scan of each requested chunk. The core scan happens
+	 * during the "execution" of the WRMSR. This instruction can
+	 * take up to 200 milliseconds (in the case where all chunks
+	 * are processed in a single pass) before it retires.
+	 */
+	wrmsrl(MSR_ACTIVATE_SCAN, msrs[0]);
+
+	if (cpu == first) {
+		/* Pass back the result of the scan */
+		rdmsrl(MSR_SCAN_STATUS, msrs[1]);
+	}
+
+	return 0;
+}
+
+/*
+ * Use stop_core_cpuslocked() to synchronize writing to MSR_ACTIVATE_SCAN
+ * on all threads of the core to be tested. Loop if necessary to complete
+ * run of all chunks. Include some defensive tests to make sure forward
+ * progress is made, and that the whole test completes in a reasonable time.
+ */
+static void ifs_test_core(int cpu, struct device *dev)
+{
+	union ifs_scan activate;
+	union ifs_status status;
+	unsigned long timeout;
+	struct ifs_data *ifsd;
+	u64 msrvals[2];
+	int retries;
+
+	ifsd = ifs_get_data(dev);
+
+	activate.rsvd = 0;
+	activate.delay = IFS_THREAD_WAIT;
+	activate.sigmce = 0;
+	activate.start = 0;
+	activate.stop = ifsd->valid_chunks - 1;
+
+	timeout = jiffies + HZ / 2;
+	retries = MAX_IFS_RETRIES;
+
+	while (activate.start <= activate.stop) {
+		if (time_after(jiffies, timeout)) {
+			status.error_code = IFS_SW_TIMEOUT;
+			break;
+		}
+
+		msrvals[0] = activate.data;
+		stop_core_cpuslocked(cpu, doscan, msrvals);
+
+		status.data = msrvals[1];
+
+		trace_ifs_status(cpu, activate, status);
+
+		/* Some cases can be retried, give up for others */
+		if (!can_restart(status))
+			break;
+
+		if (status.chunk_num == activate.start) {
+			/* Check for forward progress */
+			if (--retries == 0) {
+				if (status.error_code == IFS_NO_ERROR)
+					status.error_code = IFS_SW_PARTIAL_COMPLETION;
+				break;
+			}
+		} else {
+			retries = MAX_IFS_RETRIES;
+			activate.start = status.chunk_num;
+		}
+	}
+
+	/* Update status for this core */
+	ifsd->scan_details = status.data;
+
+	if (status.control_error || status.signature_error) {
+		ifsd->status = SCAN_TEST_FAIL;
+		message_fail(dev, cpu, status);
+	} else if (status.error_code) {
+		ifsd->status = SCAN_NOT_TESTED;
+		message_not_tested(dev, cpu, status);
+	} else {
+		ifsd->status = SCAN_TEST_PASS;
+	}
+}
+
+/*
+ * Initiate per core test. It wakes up work queue threads on the target cpu and
+ * its sibling cpu. Once all sibling threads wake up, the scan test gets executed and
+ * wait for all sibling threads to finish the scan test.
+ */
+int do_core_test(int cpu, struct device *dev)
+{
+	int ret = 0;
+
+	/* Prevent CPUs from being taken offline during the scan test */
+	cpus_read_lock();
+
+	if (!cpu_online(cpu)) {
+		dev_info(dev, "cannot test on the offline cpu %d\n", cpu);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ifs_test_core(cpu, dev);
+out:
+	cpus_read_unlock();
+	return ret;
+}
diff --git a/drivers/platform/x86/intel/ifs/sysfs.c b/drivers/platform/x86/intel/ifs/sysfs.c
new file mode 100644
index 000000000..37d8380d6
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/sysfs.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/semaphore.h>
+#include <linux/slab.h>
+
+#include "ifs.h"
+
+/*
+ * Protects against simultaneous tests on multiple cores, or
+ * reloading can file while a test is in progress
+ */
+DEFINE_SEMAPHORE(ifs_sem);
+
+/*
+ * The sysfs interface to check additional details of last test
+ * cat /sys/devices/system/platform/ifs/details
+ */
+static ssize_t details_show(struct device *dev,
+			    struct device_attribute *attr,
+			    char *buf)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+
+	return sysfs_emit(buf, "%#llx\n", ifsd->scan_details);
+}
+
+static DEVICE_ATTR_RO(details);
+
+static const char * const status_msg[] = {
+	[SCAN_NOT_TESTED] = "untested",
+	[SCAN_TEST_PASS] = "pass",
+	[SCAN_TEST_FAIL] = "fail"
+};
+
+/*
+ * The sysfs interface to check the test status:
+ * To check the status of last test
+ * cat /sys/devices/platform/ifs/status
+ */
+static ssize_t status_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+
+	return sysfs_emit(buf, "%s\n", status_msg[ifsd->status]);
+}
+
+static DEVICE_ATTR_RO(status);
+
+/*
+ * The sysfs interface for single core testing
+ * To start test, for example, cpu5
+ * echo 5 > /sys/devices/platform/ifs/run_test
+ * To check the result:
+ * cat /sys/devices/platform/ifs/result
+ * The sibling core gets tested at the same time.
+ */
+static ssize_t run_test_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+	unsigned int cpu;
+	int rc;
+
+	rc = kstrtouint(buf, 0, &cpu);
+	if (rc < 0 || cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	if (down_interruptible(&ifs_sem))
+		return -EINTR;
+
+	if (!ifsd->loaded)
+		rc = -EPERM;
+	else
+		rc = do_core_test(cpu, dev);
+
+	up(&ifs_sem);
+
+	return rc ? rc : count;
+}
+
+static DEVICE_ATTR_WO(run_test);
+
+/*
+ * Reload the IFS image. When user wants to install new IFS image
+ */
+static ssize_t reload_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+	bool res;
+
+
+	if (kstrtobool(buf, &res))
+		return -EINVAL;
+	if (!res)
+		return count;
+
+	if (down_interruptible(&ifs_sem))
+		return -EINTR;
+
+	ifs_load_firmware(dev);
+
+	up(&ifs_sem);
+
+	return ifsd->loaded ? count : -ENODEV;
+}
+
+static DEVICE_ATTR_WO(reload);
+
+/*
+ * Display currently loaded IFS image version.
+ */
+static ssize_t image_version_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+
+	if (!ifsd->loaded)
+		return sysfs_emit(buf, "%s\n", "none");
+	else
+		return sysfs_emit(buf, "%#x\n", ifsd->loaded_version);
+}
+
+static DEVICE_ATTR_RO(image_version);
+
+/* global scan sysfs attributes */
+static struct attribute *plat_ifs_attrs[] = {
+	&dev_attr_details.attr,
+	&dev_attr_status.attr,
+	&dev_attr_run_test.attr,
+	&dev_attr_reload.attr,
+	&dev_attr_image_version.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(plat_ifs);
+
+const struct attribute_group **ifs_get_groups(void)
+{
+	return plat_ifs_groups;
+}